1. Field of the Invention
The present invention relates generally to a means for collecting and processing geographical contour data used to create or update contour maps documenting land-based (topographic) and sea-based (hydrographic) elevation and depth features. In particular, the present invention provides for contour mapping utilizing horizontal position-based sensors, such as global positioning system (“GPS”) based sensors, coupled with an elevation or depth measuring sensor, such as augmented GPS, radar altimetry, or sonar, applied to a quantity of mobile air, land, or sea platforms engaged in routine activities.
2. Related Art
The topographic and hydrographic features of the earth are ever changing due to erosion, sedimentation, shoaling, and the growing influence of human activities. For example, the lack of the most current and accurate subsurface terrain data (e.g., channel depth as a function of position) at the time of a ship's transit introduces a level of uncertainty that prevents optimal safety and navigational efficiency. Similar mobility impacts result from the lack of current knowledge of the earth's land elevation features.
Current methods of measuring elevation and water depth require deliberate missions using dedicated personnel and vehicles equipped with advanced instrumentation and expertise. These missions provide for the acquisition of very accurate measurements, but do so at high cost associated with procurement and operation of the vehicles and equipment involved. In addition, the areas targeted for detailed surveying are prioritized more so based on duration of time since the last survey was performed, as opposed to being based on an indication that a detailed resurvey is required. Budget and time constraints often limit proper survey efforts to a limited number of desired mapping areas.
In the Hydrographic Services Review Panel 2007 Special Report to the National Oceanic and Atmospheric Administration (“NOAA”) Administrator, the number one recommendation was for NOAA to aggressively survey and map navigationally significant areas and shorelines by expanding in-house and contract survey capabilities to acquire and process more hydrographic mapping data. This is of such urgency due to the fact that U.S. coastal waters have never been completely surveyed, and for the areas that have been surveyed, much of the sounding data shown on NOAA nautical charts is pre-1940.
While surveying of waterways, for example, provides updated channel information, the information is typically used to revise paper charts instead of being made directly available to travelers. In the end, the lack of, or excessive latency in the delivery of updated information results in occasional grounding accidents and creates the potential for significant environmental dangers.
Therefore, what is needed is a system and method that provides updated survey information for heavily traveled land and sea areas, while maintaining within a reasonable budget and time constraint. Furthermore, what is needed is a system that is capable of expediently providing such survey information to those traveling via updated maps and nautical charts.